Applying stabilometry in characterizing floor sitting modes of women

Abstract

Abstract The study elucidates the applicability of stabiolomety in evaluating floor sitting modes and characterizing the center of pressure (CoP) displacement patterns of women in sitting. The measurement included quantifying the stabilometric dimensions while women (N=10) seated on the piezoelectric force platform in different modes—such as squatting, left leg crossed, right leg vertically bent at knee, and vice versa, both legs bent at knee without pelvic support, legs extended and locked at knee, sideways sitting with legs folded. The principal component analysis of 10 CoP dimensions yielded three-component model, describing (1) the size, radius, and range of the CoP oscillation, (2) the trajectory (trace) length and velocity of CoP displacement, and (3) the directional CoP displacement, such as anterio-posterior (AP) and medio-lateral (ML) displacements. Detailed one-way repeated measures ANOVA showed that the sitting modes had discernable effects on the amplitude deviations as well as velocity parameters derived from CoP co-ordinates. The extending of legs caused the body to move largely in the AP direction, and also markedly influenced the CoP trajectory length as well as the velocity of CoP displacements, indicating greater instability in the postures. Knee bent modes as well as sideways sitting resulted in larger ML excursion of CoP. Squatting with both legs crossed had equilateral AP and ML CoP displacement with least velocity of displacement, and identified as a more stable floor seated posture. Eleven envelopes of CoP trace patterns were characterized in terms of ML, AP, centralized, diffused, and multi-centric CoP movement from its barycenter. The CoP trace patterns did not indicate one pattern—one posture relationship; however, the centralized CoP displacement was most prevalent in squatting as well as sideways sitting postures. The diffused nature of displacement was dominant in knee bent postures. The ML butterfly and AP patterns were evenly present in extended legs, locked at knee postures and in without pelvic support knee bent posture. The first of the kind study reflects a broadened scope of stabilometry in profiling functional measures of postural balance of women in floor sitting modes. Relevance to industry The postural stability/instability is a crucial concern to mitigate risk potentials of spinal and musculo-skeletal injuries at workplaces. The stabilometry is a promising approach to ascertain and characterize women's floor sitting modes, for neurological, orthopedic, and ergonomics applications.